Search Results (588)

Bilberry (Vaccinium myrtillus L.) fruits represent the recognized wellspring of bioactive compounds with various documented bioactivities. Although bilberry leaves are often treated as industrial by-products, they also represent a valuable source of phytochemicals with potential dermocosmetic applications. In this study, extracts of bilberry fruits and leaves were prepared using both conventional solvents (water and 50% ethanol) and natural deep eutectic solvents (NaDES) as green, biodegradable alternatives. The aim of this study was to examine the UV protective activity and inhibitory potential of those extracts against some enzymes (tyrosinase, hyaluronidase, collagenase) that are important in terms of skin conditioning and skin aging. The results of in vitro tests have shown the superiority of NaDES extracts compared to conventional extracts regarding all tested bioactivities. In addition, bilberry leaves extracts were more potent compared to fruit extracts in all cases. The most potent extract was bilberry leaf extract made with malic acid–glycerol, which exhibited strong anti-tyrosinase (IC₅₀ = 3.52 ± 0.26 mg/mL), anti-hyaluronidase (IC₅₀ = 3.23 ± 0.30 mg/mL), and anti-collagenase (IC₅₀ = 1.84 ± 0.50 mg/mL) activities. The correlation analysis revealed correlation between UV protective and anti-tyrosinase, UV protective and anti-collagenase as well as between anti-hyaluronidase and anti-collagenase activity. UV protection and anti-tyrosinase activity correlated significantly with chlorogenic acid and hyperoside contents in extracts. The extracts with the best activities also demonstrated a good safety profile in a 24 h in vivo study on human volunteers. Full article

Lanthanide rare earth elements possess significant promise for material applications owing to their distinctive optical and magnetic characteristics, as well as their versatile coordination capabilities. This study introduced a lanthanide-functionalized magnetic nanocellulose composite (NNC@Fe₃O₄@La(OH)₃) for effective phosphorus/nitrogen (P/N) ligand separation. The hybrid material employs the adaptable coordination geometry and strong affinity for oxygen of La³⁺ ions to show enhanced DNA-binding capacity via multi-site coordination with phosphate backbones and bases. This study utilized cellulose as a carrier, which was modified through carboxylation and amination processes employing deep eutectic solvents (DES) and polyethyleneimine. Magnetic nanoparticles and La(OH)₃ were subsequently incorporated into the cellulose via in situ growth. NNC@Fe₃O₄@La(OH)₃ showed a specific surface area of 36.2 m²·g⁻¹ and a magnetic saturation intensity of 37 emu/g, facilitating the formation of ligands with accessible La³⁺ active sites, hence creating mesoporous interfaces that allow for fast separation. NNC@Fe₃O₄@La(OH)₃ showed a significant affinity for DNA, with adsorption capacities reaching 243 mg/g, mostly due to the multistage coordination binding of La³⁺ to the phosphate groups and bases of DNA. Simultaneously, kinetic experiments indicated that the binding process adhered to a pseudo-secondary kinetic model, predominantly dependent on chemisorption. This study developed a unique rare-earth coordination-driven functional hybrid material, which is highly significant for constructing selective separation platforms for P/N-containing ligands. Full article

The sustainable recovery of valuable metals such as Cu and Co from ores is a pressing need considering environmental and economic challenges. Therefore, this study evaluates the effectiveness of deep eutectic solvents (DESs) as alternative leaching agents for Cu and Co extraction. Four DESs were prepared using choline chloride (ChCl) as a hydrogen bond acceptor (HBA) and oxalic acid (OA), ethylene glycol (EG), urea (U) and thiourea (TU) as hydrogen bond donors (HBDs). Leaching experiments were conducted with DESs supplemented with 30 wt.% water at varying temperatures, various solid-to-liquid ratios, and time durations. The ChCl:OA DES demonstrated the highest leaching efficiencies among the DESs tested on pure CuO and CoO, achieving 89.2% for Cu and 92.4% for Co (60 °C, 400 rpm, 6 h, −75 + 53 µm particle size, and 1:10 solid-to-liquid ratio). In addition, the dissolution kinetics, analysed using the shrinking core model (SCM), showed that the leaching process was mainly controlled by surface chemical reactions. The activation energy values for Cu and Co leaching were 46.8 kJ mol⁻¹ and 51.4 kJ mol⁻¹, respectively, supporting a surface chemical control mechanism. The results highlight the potential of ChCl:OA as a sustainable alternative for metal recovery. Full article

Hydrogen energy is a pivotal carrier for achieving carbon neutrality, requiring green and efficient production via water electrolysis. However, the anodic oxygen evolution reaction (OER) involves a sluggish four-electron transfer process, resulting in high overpotentials, while the prohibitive cost and complex preparation of precious metal catalysts impede large-scale commercialization. In this study, we develop a FeCo-based bimetallic deep eutectic solvent (FeCo-DES) as a multifunctional reaction medium for engineering a three-dimensional (3D) coral-like FeOOH-Co₂(OH)₃Cl/NF composite via a mild one-step impregnation approach (70 °C, ambient pressure). The FeCo-DES simultaneously serves as the solvent, metal source, and redox agent, driving the controlled in situ assembly of FeOOH-Co₂(OH)₃Cl hybrids on Ni(OH)₂/NiOOH-coated nickel foam (NF). This hierarchical architecture induces synergistic enhancement through geometric structural effects combined with multi-component electronic interactions. Consequently, the FeOOH-Co₂(OH)₃Cl/NF catalyst achieves a remarkably low overpotential of 197 mV at 100 mA cm⁻² and a Tafel slope of 65.9 mV dec⁻¹, along with 98% current retention over 24 h chronopotentiometry. This study pioneers a DES-mediated strategy for designing robust composite catalysts, establishing a scalable blueprint for high-performance and low-cost OER systems. Full article

Pectin is a multifunctional polysaccharide whose structural attributes, including degree of esterification (DE), molecular weight (MW), and branching, directly affect its gelling, emulsifying, and bioactive properties. Conventional pectin extraction relies on acid- or alkali-based methods that degrade the pectin structure, generate chemical waste, and alter its physicochemical and functional properties. Although novel methods such as ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), and enzyme-assisted extraction (EAE) are recognized as environmentally friendly alternatives, they frequently use acids or alkalis as solvents. This review focuses on pectin extraction methods that do not involve acidic or alkaline solvents such as chelating agents, super/subcritical water, and deep eutectic solvents (DESs) composed of neutral components. This review also discusses how these alternative extraction methods can preserve or modify the key structural features of pectin, thereby influencing its monosaccharide composition, molecular conformation, and interactions with other biopolymers. Furthermore, the influence of these structural variations on the rheological properties, gelling behaviors, and potential applications of pectin in the food, pharmaceutical, and biomedical fields are discussed. This review provides insights into alternative strategies for obtaining structurally intact and functionally diverse pectin by examining the relationship between the extraction conditions and pectin functionality. Full article

Lithium-ion batteries (LiBs) are utilized in numerous applications due to advancements in technology, and the recovery of end-of-life (EoL) LiBs is imperative for environmental and economic reasons. Pyrometallurgical and hydrometallurgical methods have been used in the recovery of metals such as Li, Co, and Ni in the EoL LiBs. Hydrometallurgical methods, which have been demonstrated to exhibit higher recovery efficiency and reduced energy consumption, have garnered increased attention in recent research. Inorganic acids, including HCl, HNO₃, and H₂SO₄, as well as organic acids such as acetic acid and citric acid, are employed in the hydrometallurgical recovery of these metals. It is imperative to acknowledge the environmental hazards posed by these acids. Consequently, solvometallurgical processes, which involve the use of organic solvents with minimal or no water, are gaining increasing attention as alternative or complementary techniques to conventional hydrometallurgical processes. In the context of solvent systems that have been examined for a range of solvometallurgical methods, deep eutectic solvents (DESs) have garnered particular interest due to their low toxicity, biodegradable nature, tunable properties, and efficient metal recovery potential. In this study, the leaching process of black mass containing graphite, LCO, NMC, and LMO was carried out in a short time using the ternary DES system. The ternary DES system consists of choline chloride (ChCl), glycolic acid (GLY), and ascorbic acid (AA). As a result of the leaching process of cathode powders in the black mass without any pre-enrichment process, Li, Co, Ni, and Mn elements passed into solution with an efficiency of over 95% at 60 °C and within 1 h. Moreover, the kinetics of the leaching process was investigated, and Density Functional Theory (DFT) calculations were used to explain the leaching mechanism. Full article

In this study, the ultrasonic-assisted extraction of deep eutectic solvents (UADES) for tea polysaccharides was optimized, and their physicochemical properties and antioxidant activities were analyzed. The optimal DES comprised choline chloride (CC) and ethylene glycol (EG) in a molar ratio of 1:3, with a water content of 40%. The optimized condition was an extraction temperature of 61 °C, an ultrasonic power of 480 W, and an extraction time of 60 min. The UADES extraction rate of polysaccharides (ERP) was 15.89 ± 0.13%, significantly exceeding that of hot water (HW) extraction. The polysaccharide content in the UADES-extracted tea polysaccharides (UADESTPs) was comparable to that of hot-water-extracted tea polysaccharides (HWTPs) (75.47 ± 1.35% vs. 74.08 ± 2.51%); the UADESTPs contained more uronic acid (8.35 ± 0.26%) and less protein (12.91%) than HWTP. Most of the UADESTPs (88.87%) had molecular weights (Mw) below 1.80 × 10³ Da. The UADESTPs contained trehalose, glucuronic acid, galactose, xylose, and glucose, with molar ratios of 8:16:1:10. The free radical scavenging rate and total reducing power of the UADESTPs were markedly superior to those of the HWTPs. Moreover, the UADESTPs had a better alleviating effect on H₂O₂-induced oxidative injury in HepG2 cells. This study develops an eco-friendly and efficient extraction method for tea polysaccharides, offering new insights for the development of tea polysaccharides. Full article

Efficient and sustainable extraction of bioactive benzopyrans from Hypericum polyanthemum Klotzsch ex Reichardt (Hypericaceae) remains underexplored, despite their potential applications. The current study aimed to optimize this process by integrating computational simulation and experimental extraction with suitable solvents. The COSMO-RS model was employed to screen deep eutectic solvents (DESs), indicating lactic acid/glycine/water 3:1:3 (DES 1) as a highly promising candidate based on activity coefficients at infinite dilution for target benzopyrans (HP1, HP2, HP3). Ultrasound-assisted extraction (UAE) was then conducted using the proposed DES as well as hexane, and the extracts were analyzed via high-performance liquid chromatography (HPLC) and spectrophotometry for total phenolic content (TPC). The results for DES 1 showed yields for benzopyrans HP1 (1.43 ± 0.09 mg/g plant) and HP2 (0.55 ± 0.04 mg/g plant) close to those obtained in the hexane extract (1.65 and 0.78 mg/g plant, respectively), corroborating the use of COSMO-RS for solvent screening. Kinetic analysis using an adapted Crank diffusion model successfully described the mass transfer process for DES 1 (R² > 0.98, mean average percent error < 9%), indicating diffusion control and allowing estimation of effective diffusion coefficients. This work confirms COSMO-RS as a valuable tool for solvent selection and demonstrates that UAE with the identified DES provides an efficient, greener approach for extracting valuable benzopyrans, offering a foundation for further process optimization. Full article

Phenolic compounds are secondary metabolites widely distributed among plants, with bioactive properties, especially antioxidant activity. The search for sustainable extraction methods has driven the use of natural deep eutectic solvents (NaDESs), formed by combinations of natural compounds, such as organic acids, sugars, alcohols, and amino acids. This study optimized NaDES (sorbitol, citric acid, and glycine) efficiency and compared it to that of 70% methanol solution in extracting total soluble phenolic compounds (TSPCs) from six flours matrices—corn, buckwheat, biofortified orange sweet potato, red lentil, Sudan grass, and chickpea—before and after thermoplastic extrusion cooking. Quantification was performed using the Folin–Ciocalteu method, with statistical analysis at the 10% significance level. In general, the methanolic extracts showed higher TSPC levels in the raw materials, whereas the levels were higher in NaDESs for legumes. After extrusion, a reduction in the TSPC levels was observed, except in the sweet potato. Multivariate analysis (PLS-DA and heatmap) distinguished the raw and extruded samples, revealing structural and chemical changes from thermal processing. The AGREE scores were 0.7 (NaDES) and 0.54 (methanol), favoring NaDES. The BAGI score (75.0) confirmed the method’s robustness and suitability for sustainable analytical applications. Full article

Laurus nobilis L. is a widely cultivated plant, used for ornamental purposes, as a high-value spice crop, and in the flavor and fragrance industry. In natural medicine, it is well-known for its many beneficial properties (due to a broad spectrum of biologically active compounds) and used for the treatment of different disorders. In this study, natural deep eutectic solvents (NaDESs), coupled with microwave activation, were studied and applied for a green extraction of L. nobilis leaves. The main objective was to obtain a sustainable and multifunctional cosmetic and pharmaceutical ingredient (the NaDES-based extract itself), exploiting both the intrinsic cosmetic functionalities of NaDES components and the biological properties of laurel bioactive compounds. The most promising candidate was obtained from a eutectic system containing betaine, glycerol, and lactic acid. The evaluation of this NaDES-based complex reveals a considerable number of phenolic compounds (around 11.57 mg of gallic acid equivalents for a gram of fresh leaves) and a notable antioxidant activity (80.1% with respect to Trolox), with values quite constant over a period of six months. The complex exhibits effective antimicrobial activity against different Gram-positive (S. aureus and S. epidermidis) and Gram-negative (E. coli and P. aeruginosa) bacterial strains, with concentrations ranging from 3.8 to 7.5 mg/mL. Furthermore, the extract presents a pleasant fragrance, attributable to the selective extraction of different volatile aromatic compounds, as confirmed by GC-MS analysis. Full article

Dopamine (DA) is a neurotransmitter responsible for important functions in mammals’ bodies, including mood, movement and motivation. High or low dopamine levels are associated mainly with mental illnesses such as schizophrenia and depression. Therefore, contributing to the development of electrochemical devices to precisely determine the DA levels in urine samples, a simple and low-cost sensor is proposed in this work. The proposed sensor design is based on crosslinked chitosan films combining carbon black (CB) and deep eutectic solvents (DESs), incorporated onto the surface of a glassy carbon electrode (GCE). Fourier Transform Infrared Spectroscopy (FT-IR) was applied to characterize the produced DESs and their precursors, while the films were characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The sensor modified with CB and DES–ethaline (DES (ETHA)-CB/GCE) showed a significantly enhanced analytical signal for DA using differential pulse voltammetry under the optimized working conditions. Moreover, a better heterogeneous electron transfer rate constant (k⁰) was obtained, about 45 times higher than that of the bare GCE. The proposed sensor achieved a linear response range of 0.498 to 26.8 µmol L⁻¹ and limits of detection and quantification of 80.7 and 269 nmol L⁻¹, respectively. Moreover, the sensor was successfully applied in the quantification of DA in the synthetic urine samples, with recovery results close to 100%. Furthermore, the sensor presented good precision, as shown from the repeatability tests. The presented method to electrochemically detect DA has proven to be efficient and simple compared to the conventional methods commonly reported. Full article

Wood is a green and renewable bio-based building material, but its hygroscopicity affects its dimensional stability, limiting its use in construction. Chemical modification can improve its properties, yet its effectiveness depends on wood permeability and traditional modifiers. This study first used a deep eutectic solvent (DES) to boost the permeability of North American alder wood. Then, methyl trimethoxysilane was impregnated under supercritical carbon dioxide (SCI), pressure (PI), vacuum (VI), and atmospheric pressure (AI) conditions. DES treatment damaged the cell structure, increasing wood permeability. Silane was deposited and polymerized in the cell lumen, chemically bonding with cell-wall components, filling walls and pits, and thickening walls. The VI group had the highest absolute density (0.59 g/cm³, +36.6%) and the lowest moisture absorption (4.4%, −33.3%). The AI group had the highest ASE (25%). The PI group showed the highest surface hardness (RL, 2592 N) and a water contact angle of 131.9°, much higher than natural wood. Overall, the VI group had the best performance. Silane reacts with cellulose, hemicellulose, and lignin in wood via hydrolysis and hydroxyl bonding, forming stable bonds that enhance the treated wood’s hydrophobicity, dimensional stability, and surface hardness. Full article

The development of metallic coatings as Ni-Co alloys, with particular emphasis on their homogeneity, processability, and sustainability, is of the utmost significance. To address these challenges, the utilization of phenylsalicylimines (PSIs) as additives within deep eutectic solvents (DES) was investigated, assessing their influence on the electrodeposition process of these metals at an intermediate temperature of 60 °C, while circumventing aqueous reaction conditions. The findings demonstrated that the incorporation of PSIs markedly enhances coating uniformity, resulting in an optimal cobalt content of 37% and an average thickness of 24 µm. Electrochemical evaluations revealed improvements in charge and mass transfer, thereby optimizing process efficiency. Moreover, computational studies confirmed that PSIs form stable complexes with Co (II), modulating the electrochemical characteristics of the system through the introduction of the diethylamino electron-donating group, which significantly stabilizes the coordinated forms with both components of the DES. Additionally, the coatings displayed exceptional corrosion resistance, with a rate of 0.781 µm per year, and achieved an optimal hardness of 38 N HRC, conforming to ASTM B994 standards. This research contributes to the development of electroplating bath designs for metallic coating deposition and lays the groundwork for the advancement of sophisticated technologies in functional coatings that augment corrosion resistance and mechanical properties. Full article

Here, we demonstrated a direct method to produce cellulose nanocrystals (CNCs) with a rod-like shape from microcrystalline cellulose by a ZnCl₂-based deep eutectic solvent (DES) with a high yield (~80.1%). We obtained CNCs, crystalline index (68.9%), with a width of ~30–50 nm and a length of 200–400 nm. Importantly, we were able to functionalize the CNCs with an acetyl, -(CO)CH₃, group, which could potentially modulate the hydrophobic property of the CNCs. We attributed the formation of the CNCs to the Lewis acid effect of ZnCl₂, which can hydrolyze the amorphous cellulose regime. Our study opens a new path to directly isolate cellulose nanocrystals with several functional groups on the surface of CNCs. Full article

Utilizing deep eutectic solvents (DESs) combined with microwave-assisted extraction (MAE) provides a sustainable method for extracting bioactive compounds from the macroalgae Ascophyllum nodosum and Laminaria hyperborea. Two DES formulations, choline chloride/lactic acid (ChCl/LA) and sodium acetate/lactic acid (AcNa/LA), were evaluated under varying extraction conditions. For L. hyperborea, ChCl/LA at 150 °C for 10 min yielded a total phenolic content (TPC) of 15.34 mg GAE/g DW, with antioxidant activities measured by DPPH (34.55 mg TE/g DW) and ABTS (27.06 mg TE/g DW). Extending the extraction to 20 min at 130 °C increased the TPC to 19.12 mg GAE/g DW. A. nodosum exhibited higher bioactivity, with the TPC reaching 47.51 mg GAE/g DW under the same conditions. High-performance liquid chromatography (HPLC) identified significant phenolics such as 3,4-dihydroxybenzoic acid (678.05 µg/g DW) and vanillin (6718.5 µg/g DW). Antimicrobial assays revealed strong inhibition (zones > 20 mm) against Clostridium perfringens, moderate activity against Staphylococcus aureus, and selective activity against Escherichia coli. FT-IR confirmed the presence of phenolics, polysaccharides, and lipids. Thermal and structural characterization revealed that A. nodosum residue showed an amorphous structure, while L. hyperborea retained crystallinity with decomposition profiles indicating potential bioenergy potential. SEM images revealed significant cell wall disruption correlating with extraction efficiency. These results demonstrate DES–MAE as an effective, green strategy for producing high-value algal extracts and valorizing residual biomass for biotechnological applications. Full article